The most common reason for bleeding when you poop is hemorrhoids, which are swollen veins inside or around your anus. The second most common cause is an anal fissure, a small tear in the lining of the anal canal. Both are usually triggered by straining to pass hard stool, and neither is dangerous on its own. That said, rectal bleeding can occasionally signal something more serious, so it’s worth understanding what different symptoms mean.
Hemorrhoids: The Most Likely Cause
Hemorrhoids are the single most common reason people see blood after a bowel movement. They’re swollen blood vessels in and around the rectum that can bleed when stool passes over them. You might notice bright red blood on the toilet paper, dripping into the bowl, or coating the surface of your stool. The bleeding often looks alarming, but hemorrhoids rarely cause a dangerous amount of blood loss.
Beyond bleeding, hemorrhoids tend to cause a dull ache, itching, or a feeling of pressure around the anus. External hemorrhoids often create a visible or palpable lump near the anal opening. The itching can be persistent and is one of the more distinguishing features. Pain from hemorrhoids is typically mild to moderate, more of an ache than a sharp sensation, and it tends to come and go rather than linger for hours.
Constipation, prolonged sitting on the toilet, heavy lifting, pregnancy, and a low-fiber diet all increase your risk. In the United States, hemorrhoid disease is the fourth most common gastrointestinal reason for an outpatient doctor visit, accounting for 3.3 million visits per year. Worldwide, an estimated 4.4% of the general population has symptomatic hemorrhoids at any given time, though some studies put the figure much higher in certain countries.
Anal Fissures: Sharp Pain During and After
An anal fissure is a small tear in the skin lining the anal canal, usually caused by passing a large or hard stool. Fissures and hemorrhoids share many of the same triggers and both produce bright red blood, so they’re easily confused. The key difference is pain quality.
Fissures cause a sharp, burning pain that hits during the bowel movement and can persist for hours afterward. Hemorrhoids rarely produce that kind of sustained, intense discomfort. Fissures also tend to bleed less than hemorrhoids. You’ll usually see a small streak of blood on the toilet paper rather than blood dripping into the bowl. Unlike hemorrhoids, fissures don’t create swollen lumps and rarely itch. Instead, the dominant sensation is stinging or burning.
Most fissures heal on their own within a few weeks if you keep your stool soft and avoid straining.
What the Color of the Blood Tells You
Bright red blood generally comes from the lower part of the digestive tract: the rectum, anus, or lower colon. This is the type you’ll see with hemorrhoids, fissures, and most common causes of bleeding during a bowel movement.
Dark red or maroon blood suggests the source is higher up, possibly in the upper colon or small intestine. Black, tarry stools that have a distinct foul smell point to bleeding even higher in the digestive tract, such as the stomach or upper small intestine. The blood turns dark because it’s been partially digested on its way through. If you’re seeing black, tarry stool or dark red blood rather than bright red, the cause is less likely to be a simple hemorrhoid and warrants prompt medical attention.
Less Common but Important Causes
Inflammatory bowel disease, which includes Crohn’s disease and ulcerative colitis, can cause rectal bleeding alongside other symptoms like abdominal pain, diarrhea, fatigue, and unintentional weight loss. About 45% of people with Crohn’s disease experience some degree of blood in their stool. The bleeding from IBD tends to be accompanied by these broader, systemic symptoms rather than appearing in isolation, which distinguishes it from hemorrhoids or fissures.
Diverticulosis, a condition where small pouches form in the colon wall, affects many adults as they age. About 10% of people with diverticulosis experience some bleeding when hard stool passing through the colon erodes a blood vessel near one of these pouches. The bleeding is typically painless and temporary but can be surprisingly heavy, sometimes filling the toilet bowl with bright red blood.
Colorectal cancer is a rarer cause of rectal bleeding but one worth being aware of. The warning signs that push bleeding beyond a simple hemorrhoid include unexplained weight loss, a persistent change in bowel habits (new constipation or diarrhea lasting weeks), abdominal pain, and fatigue. Current guidelines recommend that most adults begin routine colorectal cancer screening at age 45, with colonoscopies every 10 years for those at average risk. If you have a family history of colorectal cancer, inflammatory bowel disease, or certain genetic syndromes, screening may need to start earlier.
What You Can Do at Home
For hemorrhoids and fissures, the goal is to reduce irritation, soften your stool, and promote healing. A sitz bath is one of the simplest and most effective approaches. Fill your bathtub or a plastic basin that fits over your toilet seat with 3 to 4 inches of warm water, around 104°F (40°C), and soak for 15 to 20 minutes. Plain warm water works well on its own. Adding salts or oils can actually irritate the area, so skip those unless specifically directed otherwise. You can take three to four sitz baths a day during a flare-up. Pat the area dry gently afterward rather than rubbing.
Increasing your fiber intake through fruits, vegetables, whole grains, or a fiber supplement helps keep stool soft so you don’t have to strain. Drinking plenty of water works alongside fiber to prevent constipation. Avoid sitting on the toilet for extended periods, scrolling your phone while waiting. The longer you sit, the more pressure builds on the rectal veins. When you feel the urge, go. When you’re done, get up.
Over-the-counter creams and suppositories designed for hemorrhoids can reduce swelling and itching. Witch hazel pads offer a cooling, soothing effect for external irritation.
What Happens at the Doctor’s Office
If bleeding persists for more than a week or two, recurs frequently, or comes with pain that isn’t improving, a doctor can evaluate the cause. The visit typically starts with a visual inspection of the anal area, followed by a digital rectal exam where the doctor inserts a lubricated, gloved finger into the rectum to feel for any lumps, swelling, or tenderness.
If more detail is needed, the doctor may perform an anoscopy. You’ll undress from the waist below and position yourself on a table. After applying a numbing gel, the doctor inserts a short, lubricated tube called an anoscope into the anus. The whole procedure takes 15 to 30 minutes and doesn’t require sedation. A light shines through the tube, giving the doctor a clear view of the anal canal and lower rectum. If anything looks abnormal, a small tissue sample can be taken for further analysis.
For people over 45 or those with risk factors, a colonoscopy may be recommended to examine the full length of the colon and rule out polyps or other issues higher up in the digestive tract.
Signs That Need Prompt Attention
Most rectal bleeding from hemorrhoids or fissures resolves on its own or with simple home care. But certain patterns signal something that needs a closer look: bleeding that doesn’t stop after a couple of weeks, large amounts of blood, black or tarry stools, blood accompanied by significant abdominal pain, unexplained weight loss, new changes in how often or how easily you have bowel movements, or feeling dizzy or lightheaded (which can indicate enough blood loss to affect your circulation). If you’re also vomiting blood or coughing up blood alongside rectal bleeding, that’s an emergency.